rpm: drop createrepo dependency
rpm: drop createrepo dependency

createrepo isn't directly used by this package, but by
qubes-core-dom0-linux instead. Lets keep that dependency only there,
especially when it's changed to createrepo_c.

marmarek/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin